People totally forget that new features add maintenance costs later. And I’m not only talking about business folks here but also devs.

Regarding adding features, I like the approach here: https://www.defmacro.org/2013/09/26/products.html

This is a solid post - I would say tho that sometimes the right way to view product development is through the lens of media. The bucketing approach in the article breaks down somewhat if you are not directly targeting solving a problem, but creating a medium for people to solve problems using their own creativity. So the question of features reduces down to how far the feature enhances the reach of the medium, not if they are (together or in aggregate) game changers wrt solving problems, because you as the product designer are not in then business of solving the problem, the customer is.

Yes, it's because people tend to think of features linearly. Eg "let's add one more feature". But since they tend to interact the complexity of the project grows multiplicatively.

The simplest software is no software at all. Reduce your technical debt as much as possible, and focus on simplicity. It's like the Apple principle.